Tribological issues during quick plastic forming

Quick plastic forming (QPF) was developed as a high-volume, hot blow forming process for automobile components, enabling larger volume applications than traditional superplastic forming (SPF). One critical aspect of the process is the tribological interaction between the forming tool and the aluminum blank, as this impacts formability, surface quality, and tool durability. While QPF has been successfully implemented for automobile components, many opportunities exist for improving the tribological condition during the process, including the die coating or treatment, the lubricant, and the fundamental understanding of aluminum/iron adhesion under QPF conditions (450 °C). This work reviews key tribological issues affecting QPF and identifies areas where additional research is required. This paper was presented at the International Symposium on Superplasticity and Superplastic Forming, sponsored by the Manufacturing Critical Sector at the ASM International AeroMat 2004 Conference and Exposition, June 8–9, 2004, in Seattle, WA. The symposium was organized by Daniel G. Sanders, The Boeing Company.     

Pitting Corrosion Within Bioreactors for Space Cell-Culture Contaminated by <Emphasis Type="Italic">Paenibacillus glucanolyticus</Emphasis>, a Case Report

Performing cell biology experiments in space imposes the use of hardware that essentially allows fluid exchange in a contained environment. Given the technical and logistical peculiarities, the limited opportunities and the high cost of access to space, a great effort during mission preparation of scientific studies is devoted to preventing loss of the experiment. The European Space Agency (ESA) requires, at the end of the preparation phase, the execution of an Experiment Sequence Test (EST), a dry-run version of the space experiment to check all procedures. At conclusion of the EST of our experiment ‘ENDO’ (ESA ILSRA-2009-1026), we found pitting corrosion of metal parts and biofilm formation within the cell-culture devices. The subsequent chemical (spectral assays), instrumental (OGP SmartScope) and microbiological (MALDI-TOF, 16S rRNA gene sequencing) investigations allowed the identification in contaminated material of Paenibacillus glucanolyticus, a ubiquitous, aerobic, facultative anaerobic, endospore forming, acid-producing, Gram-positive microorganism. A concurrence of P. glucanolyticus contamination and galvanic corrosion determined massive fouling, rust precipitation and damage to cells and cell-culture devices being, to our knowledge, the association between this microbe and corrosion never reported before in literature. As a consequence of the episode a critical procedure of experiment set up, i.e. hardware sterilization, was modified. The ENDO experiment was successfully launched to the International Space Station on September 2nd 2015 and returned to the PI laboratory on September 13th, with all cell culture samples in optimal condition.     

A Methodology to Analyse and Assess Pumping Management Strategies in Coastal Aquifers to Avoid Degradation Due to Seawater Intrusion Problems

Water Resources Management - In this paper we will focus on an interesting and complex problem, the analysis of coastal aquifer management alternatives in aquifers affected by seawater intrusion...     

Allergenicity of different apple cultivars assessed by means of skin prick test and sensitisation to recombinant allergens Mal d 1 and Mal d 3 in a group of Italian apple‐allergic patients

To evaluate differences in skin prick test response to apple cultivars in patients with apple allergy, 19 patients (10 adults and 9 children) underwent prick‐to‐prick skin prick test with eleven commercial and noncommercial apple cultivars, and evaluation of specific IgE to apple and recombinant apple allergens Mal d 1 and Mal d 3. The results show that different reactions might be evoked in a single patient by different apple cultivars and also separately for the peel and the pulp of a single cultivar. The cultivars were ranked according to their allergenicity level, being Jonathan, Jonagold, Golden Delicious and Fiesta the most allergenic when considering the pulp and Gala, Fiesta and Golden Delicious for the peel. Further investigations are needed to clarify if a single patient can be allergic only to well‐defined apple cultivars and which allergometric tests are necessary to ascertain this.     

Microfluidic chip for spatially and temporally controlled biochemical gradient generation in standard cell-culture Petri dishes

This paper reports the development, modeling, and testing of an original microfluidic chip capable of generating both time-evolving and spatially varying gradients in standard Petri dishes. It consists of three sets of five independently controlled parallel channels, and its architecture allows the generation of complex gradient profiles that can be flexibly positioned and dynamically altered in an open cell-chamber environment. A detailed fabrication protocol for the production of these chips using multilayer soft lithography is reported. A comprehensive computational model is also presented based on COMSOL Multiphysics software that includes both diffusion and advection of the fluid as it exits the microchannels. The results of the simulation are successfully applied to model single-channel experiments. The chip is then tested in multi-channel mode, and its ability to produce complex spatially varied concentration profiles is demonstrated. The achievement of steady state of the gradient profile in less than 5 min also allows for the dynamic variation of the profile. Finally, we apply the present chip architecture to investigate the migration of mouse neutrophils in an Interleukin-8 gradient. We report quantitatively on cell migration driven by Interleukin-8 gradient and provide migration speed distribution.     

Barium Titanate Nanoparticles: Highly Cytocompatible Dispersions in Glycol-chitosan and Doxorubicin Complexes for Cancer Therapy

In the latest years, innovative nanomaterials have attracted a dramatic and exponentially increasing interest, in particular for their potential applications in the biomedical field. In this paper, we reported our findings on the cytocompatibility of barium titanate nanoparticles (BTNPs), an extremely interesting ceramic material. A rational and systematic study of BTNP cytocompatibility was performed, using a dispersion method based on a non-covalent binding to glycol-chitosan, which demonstrated the optimal cytocompatibility of this nanomaterial even at high concentration (100 μg/ml). Moreover, we showed that the efficiency of doxorubicin, a widely used chemotherapy drug, is highly enhanced following the complexation with BTNPs. Our results suggest that innovative ceramic nanomaterials such as BTNPs can be realistically exploited as alternative cellular nanovectors.     

Skeletal Muscle Mitochondrial Energetic Efficiency and Aging

Aging is associated with a progressive loss of maximal cell functionality, and mitochondria are considered a key factor in aging process, since they determine the ATP availability in the cells. Mitochondrial performance during aging in skeletal muscle is reported to be either decreased or unchanged. This heterogeneity of results could partly be due to the method used to assess mitochondrial performance. In addition, in skeletal muscle the mitochondrial population is heterogeneous, composed of subsarcolemmal and intermyofibrillar mitochondria. Therefore, the purpose of the present review is to summarize the results obtained on the functionality of the above mitochondrial populations during aging, taking into account that the mitochondrial performance depends on organelle number, organelle activity, and energetic efficiency of the mitochondrial machinery in synthesizing ATP from the oxidation of fuels.